Reinforced concrete farms. Metal roof trusses: supporting structure of the roof According to the outline of the belt
Equivalent uniformly distributed design loads from snow deposits in pavement drops
Equivalent uniformly distributed design loads for trusses with a span of 24 m from overhead handling equipment (crane-beams) and load diagrams. Truss spacing 6 m
The scheme of distribution of wind areas of the end walls of the building to determine the wind
Estimated wind loads from the ends of buildings with the same spans on a truss bracing system located along a row of columns
Estimated wind loads from the ends of buildings at different spans to the truss bracing system located along a number of columns
Schemes of truss and truss trusses with marking of factory-made units. Breakdown of rafter and truss trusses into shipping marks and marking of mounting units
Connection schemes for the upper chords of truss trusses. Truss spacing 6 m
Connection schemes for the upper chords of truss trusses. Truss spacing 12 m
Schemes for the location of struts along the upper chords of truss trusses. Truss spacing 6 and 12 m
Scheme of connections of the 2nd type along the lower chords of roof trusses for buildings with a normal operating mode. Truss spacing 6 m
Scheme of connections of the 2nd type along the lower chords of roof trusses for buildings with a normal operating mode. Truss spacing 12 m
An example of solving the type 1 connection scheme along the lower chords of truss trusses for buildings with a normal operation mode with more than 3 spans in the temperature compartment. Step of trusses and columns 6 m
An example of solving the type 1 connection scheme along the lower chords of truss trusses for buildings with a normal operation mode with more than 3 spans in the temperature compartment. Truss spacing 6 m. Column spacing along the middle rows 12 m
An example of solving the type 1 connection scheme along the lower chords of truss trusses for buildings with a normal operation mode with more than 3 spans in the temperature compartment. Truss spacing 6 m. Truss spacing and columns 12 m
An example of solving the type 1 connection scheme along the lower chords of truss trusses for buildings with a heavy operating mode with more than 3 spans in the temperature compartment. Step of trusses and columns 6 m
An example of solving the type 1 connection scheme along the lower chords of truss trusses for buildings with a heavy operating mode with more than 3 spans in the temperature compartment. Truss spacing 6 m. Column spacing along the middle rows 12 m
An example of solving the type 1 connection scheme along the lower chords of truss trusses for buildings with a heavy operating mode with more than 3 spans in the temperature compartment. Step of trusses and columns 12 m
An example of solving the type 1 connection scheme for the lower chords of truss trusses for single-span buildings. Truss spacing 6 m
An example of solving the type 1 connection scheme for the lower chords of truss trusses for single-span buildings. Truss spacing 12 m
An example of solving the type 1 connection scheme for the lower chords of truss trusses for buildings with a heavy duty span of 24 m, with more than 3 spans in the temperature compartment. Truss spacing 6 m. Column spacing along the middle rows 12 m
An example of solving a connection scheme along the lower chords of roof trusses for buildings with a span of 24 m in the presence of overhead transport
Sections 4-4 and 5-5 - connections between trusses along the longitudinal rows of columns. Truss spacing 6 m
Sections 4-4 and 5-5 - connections between trusses along the longitudinal rows of columns. Truss spacing 12 m
Arrangement of spacers and stretch marks along the lower chords of truss trusses for type 1 connection schemes. Truss spacing 6 m
Arrangement of spacers and stretch marks along the lower chords of truss trusses for type 1 connection schemes. Truss spacing 12 m
Assortment of roof trusses for a flat roof with a span of 24 m with low-alloy steel chords
Assortment of roof trusses for a flat roof with a span of 30 m with low-alloy steel chords
Assortment of roof trusses for a flat roof with a span of 36 m with low-alloy steel chords
Rafter truss assortment with a span of 12 m for truss trusses with a span of 24 m
Assortment of truss trusses with a span of 12 m for truss trusses with a span of 30 and 36 m
Additional sprengels in farms with snow deposits in places of drops. Calculated forces and sections
Knots of truss farms of factory production. Nodes 1-5
Roof truss nodes in the field of assembly joints. Nodes 6-9
Knots of truss trusses of factory production. Knots 10-17
Scheme of nodes for supporting truss and truss trusses on overhead racks and columns
Roof truss support units. Knots 18-21
Roof truss support nodes on columns. Nodes 22 and 23
Support units of truss and truss trusses on overhead racks and columns. Knots 24-27
Roof truss support nodes on the truss truss. Knots 28-31
Support units of truss and truss trusses on overhead racks and columns in the elevated part of buildings near the drop. Knots 32-34
Attachment points for truss trusses to overhead posts along the lower part of the building at the drop. Knots 35-41
Link attachment points. Knots 42-44
Link attachment points. Knots 45-51
Link attachment points. Knots 52-55
Link attachment points. Knots 56-59
Link attachment points. Knots 60-61
Attachment points of ties and beams of the crane track. Knots 62-69
Roof truss nodes with a span of 24 m with overhead transport. Knots 70-72
Scheme of connections between trusses along the longitudinal extreme rows of columns with a step of 12 m, with intermediate half-timbered posts every 6 m. The step of trusses is 12 m. Knots 73-76
Schemes of support racks
Overhead racks SO-1,SO-2,SO-3,SO-4,SO-5,SO-6
Overhead racks SO-7 and SO-8
Support posts SO-9 and SO-10
Overhead props SO-11 and the table of assortment of overhead props
Marking holes on the upper and lower chords of roof trusses
Layout of large-panel slabs and details of their welding to the chords of roof trusses
Instructions for the calculation of assembly and factory joints of girdle corners in truss nodes
Weight indicators of truss and truss trusses
Forces in the rods of roof trusses from single loads
Bearing capacity of truss rods. Belts and racks
Bearing capacity of truss rods. Braces. Steel grade "Steel 3"
Truss steel specification
Specification of truss steel
Comparison of weight indicators when used in the temperature block of 2 brands of trusses. Truss spacing 12 m
Farm 24 meters metal
Truss span 24 m:
Metal structures consisting of lattice rods and a profile pipe are called trusses. For production, a pair of material is used, connected by special scarves. To assemble such a structure, welding is mainly used, but riveting is sometimes used. The farm helps to block any span. The length doesn't really matter. But in order to properly perform such an installation, a competent calculation is required. If the welding work is done with high quality, and the plan is made without errors, all that remains is to deliver the pipe assemblies upstairs. Then install them according to the upper harness, strictly according to the markup.
Metal trusses with a span of 24 m are used for the installation of mastic or rolled roofing on a steel profiled sheet in buildings and structures with a span of 24 meters.
The special design of the lattice, which forms a system of versatile triangles, ensures the rigidity of the truss frame under loads. If the truss lattice consists of a continuous zigzag of braces and racks facing the same direction, it is called a bracing. If the zigzag of the lattice is formed by braces facing in different directions alternately, the lattice is called triangular.
The choice of the type of truss must be economically justified, determined by its purpose and roofing material.
Unlike the installation of smaller trusses, a feature of the installation of metal trusses 24 m is the need to reinforce them with wooden plates or logs:
when mounting to a height, the truss is attached to the hook of a crane at two points, since its lower chord is stretched during lifting and tilting, while the upper chord is compressed;
during installation, the structure is reconciled: the verticality of the plane is checked, and the straightness of both belts is also controlled.
They allow deviations from the design position and size, they should not exceed the values \u200b\u200bspecified in SNiP.
Steel trusses with a span of 24 m, mmaterial for the manufacture of metal trusses
Truss steel span 24meters are most often made of rough or galvanized steel, while there can be several types of rolled products:
Taurine rental. Basically, farms from it are used in the construction of industrial buildings.
profile pipe.
Corner. Farms from a corner are ideal for the construction of outbuildings or temporary buildings.
Also, in the construction of a lightweight roof, construction trusses made of aluminum profiles are sometimes used. Their light weight greatly simplifies installation work.
Steel truss 24 m: how to calculate and choose a design
The determining factors in choosing a truss are the width of the spans and the angle of inclination of the structure for the construction of which is usedtruss with a span of 18 meters. Depending on these parameters, the type of metal structure and the cross section of its supporting pipes are selected.The choice of one or another option directly depends on the features of the project of the future structure.Provided that the calculations are made correctly, the high-quality welding work, the construction of trusses requires minimal labor and time costs: after the pipe assemblies rise to the upper piping, they are installed according to the markup.
We are ready to offer youready-made sets of arched hangars by price 1800 rub.m2 on the floor, which are always available onour warehouse. The kit includes: trusses, profiled sheet, gates, fasteners.Deliveries are made to any region of the Russian Federation. The cost of delivery according to the current tariffs of the carrier, orpickup.
We also sellarch trusses,which are always in stock in our warehouse, at the price:
Width 12 - 29 000 rub.per piece (consists of 4 parts, height 6 m in the ridge);
Width 15 - 36 000 rub. a piece (consists of 5 parts, height 7.5 m in the ridge);
Width 18 - 39 000 rub. a piece (consists of 6 parts, height 9 m in the ridge).
Ready for special orderarched trusses:
Width 20 - 55 000 rub.per piece (consists of 6 parts, height 10 m in the ridge);
GOST 23119-78
Group Zh34
STATE STANDARD OF THE UNION OF THE SSR
WELDED STEEL ROOF TRUMS WITH ELEMENTS
FROM PAIR CORNERS FOR INDUSTRIAL BUILDINGS
Specifications
Steel welded roof panties of double angles
for industrial buildings. specifications.
Valid from 01.01.1979
until 01.01.1984*
______________________________
* Expiry date removed
Gosstandart Decree
No. 353 dated 29.02.84. - Note
database manufacturer.
APPROVED AND INTRODUCED BY Decree of the State Committee of the Council of Ministers of the USSR for Construction of April 28, 1978 N 73
REPUBLICATION. November 1979
This standard applies to steel welded truss trusses with elements from paired corners connected into Taurus, with an upper chord slope of 1.5%, intended for industrial buildings with spans of 18, 24, 30 and 36 m:
with rolled and mastic roofing;
with steel and reinforced concrete columns;
with non-aggressive and slightly aggressive environments;
erected in areas with an estimated outdoor temperature of minus 65 ° C and above and seismicity up to 9 points inclusive.
Roof steel trusses must meet the requirements of GOST 23118-78 and the requirements set forth in the relevant sections of this standard.
1. Main dimensions
1. Main dimensions
1.1. Farms should be made in height:
3150 mm - for spans of buildings 18, 24, 30 and 36 m;
2250 mm - for spans of buildings 18 and 24 m.
Trusses with a height of 3150 mm for building spans of 18 and 24 m should be used in buildings in which, along with spans of 18 and 24 m, there are spans of 30 and 36 m, as well as in buildings where, according to the conditions of production technology, an increased height of the inter-truss space is required. In other cases, the choice of trusses in height for building spans of 18 and 24 m is made on the basis of the results of a comparison of the technical and economic indicators of the considered options.
1.2. Schemes and basic dimensions of trusses must correspond to those indicated in Fig.1. It is allowed to use additional elements of the lattice (sprengels, elements for fastening the ways of overhead transport, racks to reduce the estimated length of the main rods of trusses, etc.).
1.3. The division of farms into shipping elements must comply with drawing 2.
SCHEMES AND BASIC DIMENSIONS OF FARMS
DIVISION OF FARMS FOR SHIPMENT ELEMENTS
Trusses for spans of buildings 18 m
a) sent in one element
allowed
Trusses for spans of buildings 24 m
Trusses for spans of buildings 30 m
Trusses for spans of buildings 36 m
2. Technical requirements
2.1. Trusses must be manufactured in accordance with the requirements of this standard, GOST 23118-78 and SNiP III-18-75, according to working drawings of KMD approved in the prescribed manner.
2.2. The maximum deviations of the linear dimensions of trusses and their parts from the nominal ones are given in Table 1.
Table 1
Size name | Previous off | |
Length of trusses or shipping elements L, L, L; up to 8000 incl. St. 8000" 16000" | ||
Height of trusses or sending elements (on supports and field joints) H, H, H: | ||
Distance between the axes of the holes and the end of the support rib l, l, l The distance between the axes of the holes in the support rib A | ||
The distance between the axes of the holes in the belts of farms A, A, A, A, A | ||
Distance between groups of mounting holes A: up to 1600 incl. St. 1600" 2500" | ||
" 2500 " 4000 " | ||
" 4000 " 8000 " | ||
" 8000 " 16000 " | ||
" 16000 " 18000 " |
2.3. The limiting deviations of the shape and location of the surfaces of truss parts from the design ones are given in Table 2.
table 2
Deviation name | Previous off | |
up to 1000 incl. St. 1000" 1600" " 1600 " 2500 " | ||
" 2500 " 4000 " | ||
" 4000 " 8000 " | ||
" 8000 " 16000 " | ||
" 16000 " 18000 " | ||
Non-perpendicularity of the end of the support rib to the vertical axis of the truss | ||
Offset of the butts of paired corners in the truss plane: within mounting joints in other areas | ||
Offset of centering axes of truss rods in nodes |
2.4. The roughness of the machined end surface of the support rib should not be rougher than the first class according to GOST 2789-73.
2.5. The distance between the edges of the lattice details and belts in the truss nodes should be equal to 4-5 gusset thicknesses.
2.6. The upper belts of trusses with a thickness of belt corners of less than 10 mm in the places where reinforced concrete slabs are supported must be reinforced with overlays.
2.7. On the upper plane of the corners of the upper chords of the trusses, in the case of reinforced concrete slabs resting on them, transverse risks should be applied with indelible paint, indicating the center of the node.
2.8. Truss parts, depending on the design temperature, must be made of steel grades given in Table 3.
2.9. Welded joints of truss elements must be made mechanically.
It is allowed, in the absence of equipment for welding by mechanized methods, the use of manual welding.
Table 3
Name of parts | Assortment | Steel class for buildings erected at design temperature |
||
minus 40°C and above | below minus 40°С to minus 65°С |
|||
Option 1. | Option 2. | |||
Belt | GOST 8509-72 | |||
lattice element | GOST 8510-72 | C38/23 or C46/33 | ||
gusset | ||||
reference rib | C38/23 or C46/33 | |||
Butt plate | ||||
Notes:
1. Steel grades must be accepted according to SNiP II-B.3-72 and SNiP II-28-73.
2. Option 1 or 2 is selected based on the results of comparing their technical and economic indicators.
2.10. Materials for welding should be taken in accordance with SNiP II-B.3-72.
2.11. Trusses must be primed and painted.
Priming and painting must comply with the fifth class of coverage in accordance with GOST 9.032-74.
3. Completeness
3.1. Farms must be supplied by the manufacturer as a complete set.
The kit should include:
sending elements of farms;
mounting gaskets with a thickness of 4, 6 and 8 mm in an amount equal to 85, 65 and 20%, respectively, of the total number of truss support nodes;
technical documentation in accordance with the requirements of GOST 23118-78.
4. Acceptance rules
4.1. Trusses (shipping elements) to check their compliance with the requirements of this standard must be accepted by the technical control of the manufacturer individually.
4.2. The control of deviations of the linear dimensions of trusses and their parts (including the cross-sectional dimensions of rolled profiles) from the nominal ones, deviations of the shape and location of the surfaces of parts from the design ones, the quality of welded joints and surface preparation for protective coatings should be carried out before priming the trusses.
4.3. The first and every tenth farm should be subjected to a control assembly.
4.4. The consumer has the right to accept the trusses, while applying the acceptance rules and control methods established by this standard.
5. Control methods
5.1. The control of deviations of the linear dimensions of trusses and their parts from the nominal ones, deviations of the shape and location of the surfaces of parts from the design ones, as well as the roughness of the machined surface should be carried out by universal methods and means.
5.2. The quality control of the seams of welded joints and the dimensions of their sections should be carried out in accordance with SNiP III-18-75.
6. Marking, transport and storage
6.1. Manufactured trusses must be marked.
On each sending element of the farm must be applied:
Order number;
number of the KMD drawing, according to which the sending element of the truss is made;
symbolic designation of trusses according to the KMD drawing indicating the production serial number.
Each package of mounting gaskets must be marked with the order number and the number of the KMD drawing according to which the gaskets are made.
Each mounting gasket must be marked with its thickness.
An example of marking the sending element of the farm:
where 310 is the order number;
5 - KMD drawing number;
B8 - symbol;
6 - serial number of production.
On the sending element of the truss, markings must be applied on the first brace and on the outer plane of the lower chord, as well as on the package of mounting gaskets - at the top and bottom of the package.
Markings must be applied with indelible paint.
6.2. Farms (shipping elements) must be transported and stored in working position. At the same time, the trusses must be supported by wooden linings installed near the nodes, at least 50 mm thick during transportation and at least 150 mm when storing the trusses at the construction site.
The length of the lining must exceed the width of the lower chord of the trusses by at least 100 mm.
During transportation and storage, the reliability of fixing the trusses and their safety from damage must be ensured.
During transportation, the sending elements of farms must be combined into packages. The mass of the package must be agreed with the consumer and not exceed 20 tons.
Mounting gaskets must be bundled with wire.
7. Installation instructions
7.1. Truss installation must be carried out in accordance with the requirements of GOST 23118-78 and SNiP III-18-75.
7.2. Limit deviations from the design position of the mounted structures are given in Table 4.
Table 4
Deviation name | Previous off | |
Deviation of the vertical axis of the upper chord from the vertical axis of the lower chord of the truss | ||
Non-straightness of compressed chords from the truss plane on the length of the section between the fixing points L: up to 4000 incl. | ||
St. 4000" 8000" | ||
" 8000 " 12000 " |
7.3. The displacement of the outer edges of the supporting parts of the reinforced concrete pavement slabs from the transverse marks applied in accordance with clause 2.7 should not be more than 20 mm.
8. Manufacturer's warranty
8.1. The manufacturer must ensure that trusses comply with the requirements of this standard, subject to the conditions of transportation, storage and installation established by this standard.
Electronic text of the document
prepared by Kodeks JSC and verified against:
official publication
M.: Publishing house of standards, 1982
Reinforced concrete trusses are used for spans of 18, 24 and 30 m (rarely 36 l); subdivide them into segmental, arched, triangular, trapezoid and with parallel belts (Fig. 64). Depending on the manufacturing method, trusses can be solid, from semi-trusses, from blocks 6 m long and from individual elements.
Segmental, arched and polygonal trusses are designed for roofing with rolled roofing, triangular - under the roof of asbestos-cement and metal corrugated sheets. Farms with parallel belts are used in buildings with a flat coating under a rolled "dry" or water-filled roof.
To avoid a large slope of the roof in the extreme panels on the supports of the segmental trusses, small posts are provided to support the roof panels. Truss step 6 and 12 l (rarely 18 m).
The truss lattice allows to support panels with a width of 1.5 and 3 m. When the panels are supported off-node, the upper chord is additionally reinforced to absorb forces from local bending. Most pitched trusses have support nodes 0.8 m high.
Farms are made of concrete grades 300-500. The lower belt is prestressed and reinforced with bundles of high-strength wire. To reinforce the upper belt, braces and racks, welded frames made of hot-rolled steel of a periodic profile are used. In fems, embedded elements are provided, similar to beams.
The most rational in terms of material distribution are segmental and arched trusses with a broken or curvilinear upper belt. Compared to others, they have lower forces in the lattice elements and smaller bending moments in the upper chord from out-of-nodal loading, which makes it possible to make the lattice more sparse. Segment and arch trusses have a small height on the support, which allows to reduce the height of the walls; however, the curvilinearity of the upper chord complicates the formwork and reinforcement.
Rice. 64. Reinforced concrete roof trusses:
The configuration of the top chord of the trapezoidal trusses is simple, they are interchangeable with steel trusses. The disadvantages of such trusses include: a relatively powerful lattice, a large height on the support, which requires the installation of vertical connections between the trusses in the plane of the support posts; these trusses are somewhat heavier than segment trusses.
Compared to others, trusses with parallel belts consume more materials, but the formwork used for their manufacture is simple and less labor intensive.
The trusses are fastened to the columns and to the sub-rafter structures with anchor bolts and welding of embedded supporting elements (similar to the fastening of reinforced concrete beams).